This NIP defines `30303`, a parameterized replaceable event [NIP-33], referred to as Relay Statuses. Relay Statuses use tags extensively and **may** have `.content` populated with Stringified JSON.
## Purpose
To store relay meta-data and the result of subjective checks as queryable [NIP-12] events on nostr.
## Personas
- **Publishers** generate and push `30303` events. Events **should** be published at a regular interval. Events **may** be stale.
- **Consumers** aggregate `30303` for insight on relays. Some example consumers are a social client or relay status client.
## schema
### `event.created_at`
`created_at`**should** be interpreted by consumers as `updated_at`
The tags should be used to represent the Relay's abilities and meta at a point in time. Below the `tags schema` is expressed using pseudo-types for reasons of communication and brevity, for example `tagDescriptor[]`.
1.`"d" == tagId[0]` The relay URL. The `#d` tag **must** be included in the `event.tags[]` array. `tagId[1]`**must** be the relay websocket URL. The URL **should** be normalized.
2.`"t" == tagTopic[0]` Topics relevant to the relay. `tagTopic[]`**may** be included in the `event.tags[]` array. `tagTopic[1]`**should** be string. There **should** be no more than **twenty (20)**`tagTopic[]` arrays.
3.`"g" == tagGeo[0]` Relay Geo Data. `tagGeo[]`**may** be included in the `event.tags[]` array. `tagGeo[1]`**must** be string and **should** be a geohash. There **may** be strings defined in the key range `2+` (`tagGeo[2...]`) and they **must** be strings if set. `tagGeo[]` items **should** be descending by precision. There **should** be no more than **one (1)**`tagGeo[]` per event.
4.`"online" == tagOnline[0]` Is the relay online. `tagOnline[]`**may** be included in the `event.tags[]` array. `tagOnline[1]`**must** be type string as exactly `true` or `false`
5.`"read" == tagRead[0]` Was able to read from the relay. `tagRead[]`**may** be included in the `event.tags[]` array. `tagRead[1]`**must** be type string as exactly `true` or `false`
6.`"write" == tagWrite[0]` Was able to write to the relay. `tagWrite[]`**may** be included in the `event.tags[]` array. `tagWrite[1]`**must** be type string as exactly `true` or `false`
7.`"ssl" == tagSsl[0]` Is the relay's SSL valid. `tagSsl[]`**may** be included in the `event.tags[]` array. `tagSsl[1]`**must** be type string as exactly `true` or `false`
8.`"ip" == tagIp[0]` Relay IP. `tagIp[]`**may** be included in the `event.tags[]` array. `tagIp[1]`**must** be string. There **may** be more than one (1) `tagIp[]`
9.`"events" == tagEvents[0]` Number of events on relay. `tagEvents[]`**may** be included in the `event.tags[]` array. `tagEvents[1]`**must** be string. There **should** only be **one (1)**`tagEvents[]`
10.`"users" == tagUsers[0]` Relay IP. `tagUsers[]`**may** be included in the `event.tags[]` array. `tagUsers[1]`**must** be string. There **should** be no more than **one (1)**`tagUsers[]`
The `.content` of these events **may** be empty. `.content`**may** contain stringified JSON. The parsed JSON has a flexible schema, all members are optional. The parsed `.content` JSON **should** be extended by NIPs.
## Testing Criteria
The testing criteria to determine conditions defined in event's tags **may** be subjective and **may** vary between publishers.
The data in `30303`**may** be erroneous, intentionally or otherwise. When accuracy is required, the data in `30303` events **should** be subscribed to by populating the `authors` filter array with the pubkeys of trusted **publishers**
- A lite social client identifies relays that were recently reported to be online without client-side tests
- A social client may find relays where a particular topic is popular.
- A social client may find relays based on their geographic proximity
- A status client shows relay statuses
- Identify macro-patterns amongst relays.
- Relays self-report statuses and/or metadata in `.content` signed by their NIP-11 `pubkey`.
- Could be used to store user checks for a relay to express personalized policies. For example, a user's pubkey was blacklisted on a relay, so they were unable to write: `..., tags: { [ ["d","wss://relay.damus.io"], ["o","true"], ["w","false"] ] }, ...`.